Response To Exercise Research Articles

The cardiovascular exercise response in children with overweight or obesity measured by cardiovascular magnetic resonance imaging.

Overweight and obesity are among the main causes of cardiovascular diseases. Exercise testing can aid in the early detection of subtle cardiac dysfunction not present in rest. We hypothesized that the cardiovascular response to exercise is impaired among children with overweight or obesity, characterized by the inability of the cardiovascular system to adapt to exercise by increasing cardiac volumes and blood pressure. We performed a cardiovascular stress test to investigate whether the cardiovascular exercise response is altered in children with overweight and obesity, as compared to children with a normal weight. A subgroup of the Generation R population-based prospective cohort study, consisting of 41 children with overweight or obesity and 166 children with a normal weight with a mean age of 16 years, performed an isometric exercise. Continuous heart rate and blood pressure were measured during rest, exercise and recovery. Cardiovascular magnetic resonance (CMR) measurements were performed during rest and exercise. Higher BMI was associated with a higher resting systolic and diastolic blood pressure (difference: 0.24 SDS (95% CI 0.10, 0.37) and 0.20 SDS (95% CI 0.06, 0.33)) and lower systolic and diastolic blood pressure increases from rest to peak exercise (-0.11 SDS (95% CI -0.20, -0.03) and -0.07 SDS (95% CI -0.07, -0.01)). BMI was also associated with a slower decrease in systolic and diastolic blood pressure during recovery (p values < 0.05). Higher childhood BMI was associated with lower BSA corrected left ventricular mass, end-diastolic volume and stroke volume (p values < 0.05). There were no associations of childhood BMI with the cardiac response to exercise measured by heart rate and CMR measurements. Childhood BMI is, across the full range, associated with a blunted blood pressure response to static exercise but there were no differences in cardiac response to exercise. Our findings suggest that adiposity may especially affect the vascular exercise reaction without affecting cardiac response.

Exercise responses to repeated cycle sprints with continuous and intermittent hypoxic exposure.

We examine the impact of the acute manipulation of oxygen availability during discrete phases (active and passive) of a repeated-sprint cycling protocol on performance, physiological, and perceptual responses. On separate days, twelve trained males completed four sets of five 5-s 'all out' cycle sprints (25-s inter-sprint recovery and 5-min interset rest) in four randomized conditions: normobaric hypoxia (inspired oxygen fraction of 12.9%) applied continuously (C-HYP), intermittently during only the sets of sprints (I-HYPSPRINT) or between-sets recovery periods (I-HYPRECOVERY), or not at all (C-NOR). Peak and mean power output, peripheral oxygen saturation, heart rate, blood lactate concentration, exercise-related sensations, and vastus lateralis muscle oxygenation using near-infrared spectroscopy were assessed. Peak and mean power output was ∼4%-5% lower for C-HYP compared to C-NOR (P≤0.050) and I-HYPRECOVERY (P≤0.027). Peripheral oxygen saturation was lower during C-HYP and I-HYPSPRINT compared with C-NOR and I-HYPRECOVERY during sets of sprints (∼83-85 vs. ∼95%-97%; P<0.001), while lower values were obtained for C-HYP and I-HYPRECOVERY than C-NOR and I-HYPSPRINT during between-sets rest period (∼84-85 vs. ∼96%; P<0.001). Difficulty in breathing was ∼21% higher for C-HYP than C-NOR (P=0.050). Ratings of perceived exertion (P=0.435), limb discomfort (P=0.416), heart rate (P=0.605), blood lactate concentration (P=0.976), and muscle oxygenation-derived variables (P=0.056 to 0.605) did not differ between conditions. In conclusion, the method of hypoxic exposure application (continuous vs. intermittent) affects mechanical performance, while internal demands remained essentially comparable during repeated cycle sprints.

Loss of Calpain 3 dysregulates store-operated calcium entry and its exercise response in mice.

Limb-Girdle Muscular Dystrophy R1/2A (LGMD R1/2A) is caused by mutations in the CAPN3 gene encoding Calpain 3, a skeletal-muscle specific, Ca2+-dependent protease. Localization of Calpain 3 within the triad suggests it contributes to Ca2+ homeostasis. Through live-cell Ca2+ measurements, muscle mechanics, immunofluorescence, and electron microscopy (EM) in Capn3 deficient (C3KO) and wild-type (WT) mice, we determined whether loss of Calpain 3 altered Store-Operated Calcium Entry (SOCE) activity. Direct Ca2+ influx measurements revealed loss of Capn3 elicits elevated resting SOCE and increased resting cytosolic Ca2+, supported by high incidence of calcium entry units (CEUs) observed by EM. C3KO and WT mice were subjected to a single bout of treadmill running to elicit SOCE. Within 1HR post-treadmill running, C3KO mice exhibited diminished force production in extensor digitorum longus muscles and a greater decay of Ca2+ transients in flexor digitorum brevis muscle fibers during repetitive stimulation. Striking evidence for impaired exercise-induced SOCE activation in C3KO mice included poor colocalization of key SOCE proteins, stromal-interacting molecule 1 (STIM1) and ORAI1, combined with disappearance of CEUs in C3KO muscles. These results demonstrate that Calpain 3 is a key regulator of SOCE in skeletal muscle and identify SOCE dysregulation as a contributing factor to LGMD R1/2A pathology.

Effects of short-term dietary nitrate supplementation on exercise and coronary blood flow responses in patients with peripheral artery disease.

Peripheral arterial disease (PAD) is a prevalent vascular disorder characterized by atherosclerotic occlusion of peripheral arteries, resulting in reduced blood flow to the lower extremities and poor walking ability. Older patients with PAD are also at a markedly increased risk of cardiovascular events, including myocardial infarction. Recent evidence indicates that inorganic nitrate supplementation, which is abundant in certain vegetables, augments nitric oxide (NO) bioavailability and may have beneficial effects on walking, blood pressure, and vascular function in patients with PAD. We sought to determine if short-term nitrate supplementation (via beetroot juice) improves peak treadmill time and coronary hyperemic responses to plantar flexion exercise relative to placebo (nitrate-depleted juice) in older patients with PAD. The primary endpoints were peak treadmill time and the peak coronary hyperemic response to plantar flexion exercise. Eleven PAD patients (52-80 yr.; 9 men/2 women; Fontaine stage II) were randomized (double-blind) to either nitrate-rich (Beet-IT, 0.3 g inorganic nitrate twice/day; BRnitrate) or nitrate-depleted (Beet-IT, 0.04 g inorganic nitrate twice/day, BRplacebo) beetroot juice for 4 to 6 days, followed by a washout of 7 to 14 days before crossing over to the other treatment. Patients completed graded plantar flexion exercise with their most symptomatic leg to fatigue, followed by isometric handgrip until volitional fatigue at 40% of maximum on day 4 of supplementation, and a treadmill test to peak exertion 1-2 days later while continuing supplementation. Hemodynamics and exercise tolerance, and coronary blood flow velocity (CBV) responses were measured. Although peak walking time and claudication onset time during treadmill exercise did not differ significantly between BRplacebo and BRnitrate, the diastolic blood pressure response at the peak treadmill walking stage was significantly lower in the BRnitrate condition. Increases in CBV from baseline to peak plantar flexion exercise after BRplacebo and BRnitrate showed a trend for a greater increase in CBV at the peak workload of plantar flexion with BRnitrate (p = 0.06; Cohen's d = 0.56). Overall, these preliminary findings suggest that inorganic nitrate supplementation in PAD patients is safe, well-tolerated, and may improve the coronary hyperemic and blood pressure responses when their calf muscles are most predisposed to ischemia.Clinical trial registration:https://clinicaltrials.gov/, identifier NCT02553733.

Fat loss and muscle gain: The possible role of striatal dopaminergic tone in determining the efficacy of physical exercise

The effectiveness of exercise for obesity is contentious due to individual response variability. Owing to the roles of dopamine in motor functions, metabolism, and appetite, this study aimed to identify striatal dopamine as a predictor of variability in exercise response, specifically in terms of fat loss and muscle gain. Healthy non-exercising males completed an 8-week program, exercising 1 h, 4 days a week. Striatal dopaminergic tone was assessed by measuring dopamine transporter availability using technetium-99 m labelled tropane derivative, [99mTc]TRODAT-1 (TRODAT), single-photon emission computed tomography, and body composition (fat and muscles mass) was analysed using bioelectrical impedance. Lower baseline dopamine levels were associated with greater fat mass loss (r = 0.58, p = 0.006), percentage fat mass loss (r = 0.53, p = 0.013), and increase in muscle mass (β = -0.53, p = 0.035, after taking age and smoking status as covariates). These findings enhance our understanding of obesity neurobiology and exercise response variability, necessitating further research for targeted interventions based on dopaminergic profiles.

Autonomous Fontan pump: Computational feasibility study

ObjectiveAfter Fontan palliation, patients with single-ventricle physiology are committed to chronic circulatory inefficiency for the duration of their lives. This is due in large part to the lack of a subpulmonary ventricle. A low-pressure rise cavopulmonary assist device can address the subpulmonary deficit and offset the Fontan paradox. We investigated the feasibility of a Fontan pump that is self-powered by tapping reserve pressure energy in the systemic arterial circulation. MethodsA double-inlet, double-outlet rotary pump was designed to augment Fontan flow through the total cavopulmonary connection. Pump power is supplied by a systemic arterial shunt and radial turbine, with a closed-loop shunt return to the common atrium (QP:QS 1:1). Computational fluid dynamic analysis and lumped parameter modeling of pump impact on the Fontan circulation was performed. ResultsFindings indicate that a pump that can augment all 4 limbs of total cavopulmonary connection flow (superior vena cava/inferior vena cava inflow; left pulmonary artery/right pulmonary artery outflow) using a systemic arterial shunt powered turbine at a predicted cavopulmonary pressure rise of +2.5 mm Hg. Systemic shunt flow is 1.43 lumped parameter model, 22% cardiac output. Systemic venous pressure is reduced by 1.4 mm Hg with improved ventricular preload and cardiac output. ConclusionsIt may be possible to tap reserve pressure energy in the systemic circulation to improve Fontan circulatory efficiency. Further studies are warranted to optimize, fabricate, and test pump designs for hydraulic performance and hemocompatibility. Potential benefits of an autonomous Fontan pump include durable physiologic shift toward biventricular health, freedom from external power, autoregulating function and exercise responsiveness, and improved quality and duration of life.

The delta concept does not effectively normalise exercise responses to exhaustive interval training

ObjectivesThis study was designed to quantify inter- and intra-individual variability in performance, physiological, and perceptual responses to high-intensity interval training prescribed using the percentage of delta (%Δ) method, in which the gas exchange threshold and maximal oxygen uptake (V̇O2max) are taken into account to normalise relative exercise intensity. DesignRepeated-measures, within-subjects design with mixed-effects modelling. MethodsEighteen male and four female cyclists (age: 36 ± 12 years, height: 178 ± 10 cm, body mass: 75.2 ± 13.7 kg, V̇O2max: 51.6 ± 5.3 ml·kg−1·min−1) undertook an incremental test to exhaustion to determine the gas exchange threshold and V̇O2max as prescription benchmarks. On separate occasions, participants then completed four high-intensity interval training sessions of identical intensity (70 %Δ) and format (4-min on, 2-min off); all performed to exhaustion. Acute high-intensity interval training responses were modelled with participant as a random effect to provide estimates of inter- and intra-individual variability. ResultsGreater variability was generally observed at the between- compared with the within-individual level, ranging from 50 % to 89 % and from 11 % to 50 % of the total variability, respectively. For the group mean time to exhaustion of 20.3 min, inter- and intra-individual standard deviations reached 9.3 min (coefficient of variation = 46 %) and 4.5 min (coefficient of variation = 22 %), respectively. ConclusionsDue to the high variability observed, the %Δ method does not effectively normalise the relative intensity of exhaustive high-intensity interval training across individuals. The generally larger inter- versus intra-individual variability suggests that day-to-day biological fluctuations and/or measurement errors cannot explain the identified shortcoming of the method.

Skeletal muscle BMAL1 is necessary for transcriptional adaptation of local and peripheral tissues in response to endurance exercise training

ObjectiveIn this investigation, we addressed the contribution of the core circadian clock factor, BMAL1, in skeletal muscle to both acute transcriptional responses to exercise and transcriptional remodeling in response to exercise training. Additionally, we adopted a systems biology approach to investigate how loss of skeletal muscle BMAL1 altered peripheral tissue homeostasis as well as exercise training adaptations in iWAT, liver, heart, and lung of male mice. MethodsCombining inducible skeletal muscle specific BMAL1 knockout mice, physiological testing and standardized exercise protocols, we performed a multi-omic analysis (transcriptomics, chromatin accessibility and metabolomics) to explore loss of muscle BMAL1 on muscle and peripheral tissue responses to exercise. ResultsMuscle-specific BMAL1 knockout mice demonstrated a blunted transcriptional response to acute exercise, characterized by the lack of upregulation of well-established exercise responsive transcription factors including Nr4a3 and Ppargc1a. Six weeks of exercise training in muscle-specific BMAL1 knockout mice induced significantly greater and divergent transcriptomic and metabolomic changes in muscle. Surprisingly, liver, lung, inguinal white adipose and heart showed divergent exercise training transcriptomes with less than 5% of ‘exercise-training’ responsive genes shared for each tissue between genotypes. ConclusionsOur investigation has uncovered the critical role that BMAL1 plays in skeletal muscle as a key regulator of gene expression programs for both acute exercise and training adaptations. In addition, our work has uncovered the significant impact that altered exercise response in muscle and its likely impact on the system plays in the peripheral tissue adaptations to exercise training. Our work also demonstrates that if the muscle adaptations diverge to a more maladaptive state this is linked to increased gene expression signatures of inflammation across many tissues. Understanding the molecular targets and pathways contributing to health vs. maladaptive exercise adaptations will be critical for the next stage of therapeutic design for exercise mimetics.

Clusters of multidimensional exercise response patterns and estimated heart failure risk in the Framingham Heart Study.

New tools are needed to identify heart failure (HF) risk earlier in its course. We evaluated the association of multidimensional cardiopulmonary exercise testing (CPET) phenotypes with subclinical risk markers and predicted long-term HF risk in a large community-based cohort. We studied 2532 Framingham Heart Study participants [age 53±9years, 52% women, body mass index (BMI) 28.0±5.3kg/m2, peak oxygen uptake (VO2) 21.1±5.9kg/m2 in women, 26.4±6.7kg/m2 in men] who underwent maximum effort CPET and were not taking atrioventricular nodal blocking agents. Higher peak VO2 was associated with a lower estimated HF risk score (Spearman correlation r: -0.60 in men and -0.55 in women, P<0.0001), with an observed overlap of estimated risk across peak VO2 categories. Hierarchical clustering of 26 separate CPET phenotypes (values residualized on age, sex, and BMI to provide uniformity across these variables) identified three clusters with distinct exercise physiologies: Cluster 1-impaired oxygen kinetics; Cluster 2-impaired vascular; and Cluster 3-favourable exercise response. These clusters were similar in age, sex distribution, and BMI but displayed distinct associations with relevant subclinical phenotypes [Cluster 1-higher subcutaneous and visceral fat and lower pulmonary function; Cluster 2-higher carotid-femoral pulse wave velocity (CFPWV); and Cluster 3-lower CFPWV, C-reactive protein, fat volumes, and higher lung function; all false discovery rate<5%]. Cluster membership provided incremental variance explained (adjusted R2 increment of 0.10 in women and men, P<0.0001 for both) when compared with peak VO2 alone in association with predicted HF risk. Integrated CPET response patterns identify physiologically relevant profiles with distinct associations to subclinical phenotypes that are largely independent of standard risk factor-based assessment, which may suggest alternate pathways for prevention.

Long-term student performance prediction using learning ability self-adaptive algorithm

Predicting student performance is crucial for both preventing failure and enabling personalized teaching-and-learning strategies. The digitalization of educational institutions has led to the collection of extensive student learning data over the years. Current research primarily focuses on short-term data, e.g. a single year or semester. In contrast, long-term data has the potential to offer a deeper insight into student behavior, thereby increasing the accuracy of predictions. However, the direct application of long-term data in prediction models assumes consistent data distributions over time. In the real world, evolutions in course content and structure can lead to variations in feature spaces (heterogeneity) and distribution shifts across different academic years, compromising the effectiveness of prediction models. To address these challenges, we introduce the Learning Ability Self-Adaptive Algorithm (LASA), which can adapt to the evolving feature spaces and distributions encountered in long-term data. LASA comprises two primary components: Learning Ability Modeling (LAM) and Long-term Distribution Alignment (LTDA). LAM assumes that students’ responses to exercises are samples from distributions that are parameterized by their learning abilities. It then estimates these parameters from the heterogeneous student exercise response data, thereby creating a new homogeneous feature space to counteract the heterogeneity present in long-term data. Subsequently, LTDA employs multiple asymmetric transformations to align distributions of these new features across different years, thus mitigating the impact of distribution shifts on the model’s performance. With these steps, LASA can generate well-aligned features with meaningful semantics. Furthermore, we propose an interpretable prediction framework including three components, i.e. LASA, a base classifier for outcome predictions, and Shapley Additive Explanations (SHAP) for elucidating the impact of specific features on student performance. Our exploration of long-term student data covers an eight-year period (2016-2023) from a face-to-face course at Tsinghua University. Comprehensive experiments demonstrate that leveraging long-term data significantly enhances prediction accuracy compared to short-term data, with LASA achieving up to a 7.9% increase. Moreover, when employing long-term data, LASA outperforms state-of-the-art models, ProbSAP and SFERNN, by an average accuracy improvement of 6.8% and 6.4%, respectively. We also present interpretable insights for pedagogical interventions based on a quantitative analysis of feature impacts on student performance. To the best of our knowledge, this study is the first to investigate student performance prediction in long-term data scenarios, addressing a significant gap in the literature.

Dose/Exposure Relationship of Exercise and Distant Recurrence in Primary Breast Cancer.

Postdiagnosis exercise is associated with lower breast cancer (BC) mortality but its link with risk of recurrence is less clear. We investigated the impact and dose-response relationship of exercise and recurrence in patients with primary BC. Multicenter prospective cohort analysis among 10,359 patients with primary BC from 26 centers in France between 2012 and 2018 enrolled in the CANcer TOxicities study, with follow-up through October 2021. Exercise exposure was assessed using the Global Physical Activity Questionnaire-16, quantified in standardized metabolic equivalent of task-hours per week (MET-h/wk). We examined the dose/exposure response of pretreatment exercise on distant recurrence-free interval (DRFI) for all patients and stratified by clinical subtype and menopausal status using inverse probability treatment weighted multivariable Cox models to estimate hazard ratios (HRs). For the overall cohort, the relationship between exercise and DRFI was nonlinear: increasing exercise ≥ 5 MET-h/wk was associated with an inverse linear reduction in DRFI events up to approximately 25 MET-h/wk; increasing exercise over this threshold did not provide any additional DRFI benefit. Compared with <5 MET-h/wk, the adjusted HR for DRFI was 0.82 (95% CI, 0.61 to 1.00) for ≥ 5 MET-h/wk. Stratification by subtype revealed the hormone receptor-/human epidermal growth factor receptor 2- (HR-/HER2-; HR, 0.59 [95% CI, 0.38 to 0.92]) and HR-/HER2+ (HR, 0.37 [95% CI, 0.14 to 0.96]) subtypes were preferentially responsive to exercise. The benefit of exercise was observed especially in the premenopausal population. Postdiagnosis/pretreatment exercise is associated with lower risk of DRFI events in a nonlinear fashion in primary BC; exercise has different impact on DRFI as a function of subtype and menopausal status.

Exercise response in post-acute coronary syndrome patients survived to COVID-19 infection

AimsMany studies evaluated the functional response in post-Covid-19 patients; however, they systematically excluded patients with concomitant acute coronary syndrome (ACS).We evaluated the long-term functional capacity assessed by cardiopulmonary exercise test (CPET) in patients hospitalized for ACS and concomitant SARS-CoV2 infection. The secondary aim was to investigate the functional response in patients with symptoms related to “long COVID-19 syndrome” (LCS). MethodsThis cross-sectional case-control study compared 20 patients with ACS and concomitant SARS-COV2 infection with 20 patients without COVID-19. At the follow-up visit (between 6 and 12 months after revascularization procedure) all patients underwent a CPET. ResultsPatients with previous ACS and concomitant COVID-19 showed a reduced O2 consumption than controls (predicted peak V̇O2 74.00% vs 86.70%; p = 0.01) with a high degree of ventilatory inefficiency (VE/ V̇CO2 slope 38.04 vs 30.31; p = 0.002).50% of subjects with previous COVID-19 disease showed symptoms related to “LCS”; this subgroup demarcates the characteristic reduced exercise capacity found in the entire COVID + group. ConclusionsThis study is the first in literature having analyzed the long-term functional capacity phenotype in a population of ACS patients and concomitant SARS-CoV2 infection. Severe ventilatory inefficiency emerged as the functional signature of these patients. Moreover, the subset of patients with symptoms related to LCS has the most compromised long term reduced exercise capacity and an altered ventilation control.

Exercise Capacity Following Pulmonary Embolism in Children and Adolescents

BackgroundSelf-reported physical activity following pediatric pulmonary embolism(PE) is reduced after diagnosis. However, objectively measured exercise capacity and mechanisms of exercise pathophysiology following PE are unknown. Research QuestionDoes exercise capacity one year after acute PE in children differ from controls? Study Design and MethodsOur case-control study compared exercise capacity and responses to maximal exercise in PE survivors with controls. We also investigated the association of low exercise capacity following PE with prespecified clinical/radiological features at PE diagnosis and elucidated the cause of functional limitations. The primary study outcome was exercise capacity defined by peak oxygen uptake (peak VO2) as a percent of predicted on cardiopulmonary exercise testing (CPET), with <80% predicted peak VO2 considered abnormal/low. Ventilatory inefficiency was defined as VE/VCO2 slope >30 and abnormal stroke volume augmentation as oxygen pulse <10 mL O2.min -1 at peak exercise. Logistic regression was performed to assess the association of prespecified variables with low peak VO2. ResultsWe compared 25 consecutive pediatric PE survivors who completed CPET one-year post-diagnosis with 25 controls who underwent CPET within the same period and were otherwise healthy. Exercise capacity was reduced in 8 of the 25 PE survivors (32%) at one-year post-diagnosis vs. 2 of the 25 control participants (8%) (p:0.034). PE survivors with low exercise capacity demonstrated elevated VE/VCO2 slope (p: 0.01) and a decreased oxygen pulse at peak exercise (p:0.001) consistent with cardiovascular limitation. In univariable analysis, PE category, pulmonary vascular obstruction by Qanadli index, or RV dysfunction at diagnosis was not associated with low exercise capacity. InterpretationAbnormal exercise capacity of cardiopulmonary origin occurred in 1 of 3 pediatric PE survivors despite anticoagulation and irrespective of PE severity, degree of pulmonary vascular obstruction, or RV dysfunction at diagnosis. Cardiorespiratory fitness should be formally considered to develop rehabilitation interventions following pediatric PE.

Ten questions about cardiopulmonary exercise testing: all that the cardiologist dares or dares not to ask

In patients with cardiovascular, pulmonary, muscular and neurological diseases, cardiopulmonary exercise testing (CPET) is a valuable tool providing clinically-relevant diagnostic and prognostic information by evaluation of exercise response. CPET requires to be performed in dedicated centers able to correctly carry out the examination and to carefully evaluate the results. CPET analyzes functional capacity revealing both symptomatic and asymptomatic intolerance to exercise. One of the most important advantages for clinicians derived by the use of CPET, beyond standard exercise electrocardiography testing, is the capability not only to grade the severity of the disease, but also to distinguish between different causes of dyspnea and exercise impairment. Indications for CPET use in clinical practice are increasing in the last decades, evolving beyond the routine use as a training tool in athletes. In fact, CPET represents an important step in the management of patients with heart failure or pulmonary hypertension, as suggested by international guidelines. CPET role in helping for the selection of patients candidate to heart transplantation is also well known. Beyond its clinical usefulness, scientific interest in CPET is constantly expanding, mainly due to the safety of the exam and to the huge size of the pathophysiological information that it offers. The aim of this paper is to simply explain everyday applications and potential further purposes of CPET in clinical practice. Our review is intended both for physicians approaching CPET for the first time and for clinicians with an interest in expanding their knowledge in this field.

Association of Reduced Left Atrial Reserve With Exercise Intolerance and Outcome in Hypertension

Hypertensive heart disease (HHD) is a leading contributor to heart failure with preserved ejection fraction (HFpEF). However the mechanisms behind the transition to the symptomatic phase remain unclear. We sought the association of the exercise response of LA mechanical function with functional capacity, symptoms and outcome across the HF spectrum in hypertension. Echocardiography (including LA reservoir [PALS] and contractile strain [PACS], and LA stiffness index) were performed at rest and immediately post-exercise in 139 patients with HHD- 35 with stage A, 48 with stage B and 56 with stage C HFpEF. Patients were followed for HF and atrial fibrillation (AF). Exercise capacity was progressively worse from stage A through stage B to stage C, and accompanied by a gradual impairment of changes in PALS and PACS from rest to exercise, whereas LA stiffness reserve remained unchanged until stage C. PALS and PACS reserves were independently associated with exercise capacity(p=0.017 and 0.008, respectively). LA stiffness reserve and E/e' were the strongest associations of symptomatic HF. Over a median of 25 months, 35 patients developed HF and/or AF. PALS and PACS reserves were associated with the study endpoints after adjusting for age, diabetes, NT-proBNP, LA volume index, resting E/e' and resting PALS/PACS. Impaired exercise reserve of LA strain and stiffness are associated with reduced functional capacity in hypertension, and LA strain reserve is independently associated with outcome. These parameters appear to be determinants of progression to overt HF in HHD, however their contribution may differ depending on HF stage.

Exercise Responses During Outdoor Versus Virtual Reality Indoor Arm+FES-Leg Cycling in Individuals with Spinal Cord Injury.

Background: Virtual reality (VR)-enhanced indoor hybrid cycling in people with spinal cord injury (SCI) can be comparable to outdoor hybrid cycling. Method: Eight individuals with chronic thoracic-lesion SCI performed voluntary arm and electrically assisted leg cycling on a hybrid recumbent tricycle. Exercises were conducted outdoors and indoors incorporating VR technology in which the outdoor environment was simulated on a large flat screen monitor. Electrical stimulation was applied bilaterally to the leg muscle groups. Oxygen uptake (VO2), heart rate, energy expenditures, and Ratings of Perceived Exertion were measured over a 30-minute outdoor test course that was also VR-simulated indoors. Immediately after each exercise, participants completed questionnaires to document their perceptual-psychological responses. Results: Mean 30-minute VO2 was higher for indoor VR exercise (average VO2-indoor VR-exercise: 1316 ± mL/min vs. outdoor cycling: 1255 ± 53 mL/min; highest VO2-indoor VR-exercise: 1615 ± 67 mL/min vs. outdoor cycling: 1725 ± 67 mL/min). Arm and leg activity counts were significantly higher during indoor VR-assisted hybrid functional electrical stimulation (FES) cycling than outdoors; 42% greater for the arms and 23% higher for the legs (P < 0.05). Similar responses were reported for exercise effort and perceptual-psychological outcomes during both modes. Conclusion: This study proposes that combining FES and VR technology provides new opportunities for physical activity promotion or exercise rehabilitation in the SCI population, since these modes have similar "dose-potency" and self-perceived effort. Human Research Ethics Committee of the University of Sydney Ref. No. 01-2010/12385.

Lower vascular conductance responses to handgrip exercise are improved following acute antioxidant supplementation in young individuals with post-traumatic stress disorder.

Young individuals with post-traumatic stress disorder (PTSD) display peripheral vascular and autonomic nervous system dysfunction, two factors potentially stemming from a redox imbalance. It is currently unclear if these aforementioned factors, observed at rest, alter peripheral haemodynamic responses to exercise in this population. This study examined haemodynamic responses to handgrip exercise in young individuals with PTSD following acute antioxidant (AO) supplementation. Thirteen young individuals with PTSD (age 23±3years), and 13 age- and sex-matched controls (CTRL) participated in the study. Exercise-induced changes to arm blood flow (BF), mean arterial pressure (MAP) and vascular conductance (VC) were evaluated across two workloads of rhythmic handgrip exercise (3 and 6kg). The PTSD group participated in two visits, consuming either a placebo (PL) or AO prior to their visits. The PTSD group demonstrated significantly lower VC (P=0.04) across all exercise workloads (vs. CTRL), which was significantly improved following AO supplementation. In the PTSD group, AO supplementation improved VC in participants possessing the lowest VC responses to handgrip exercise, with AO supplementation significantly improving VC responses (3 and 6kg: P<0.01) by blunting elevated exercise-induced MAP responses (3kg: P=0.01; 6kg: P<0.01). Lower VC responses during handgrip exercise were improved following AO supplementation in young individuals with PTSD. AO supplementation was associated with a blunting of exercise-induced MAP responses in individuals with PTSD displaying elevated MAP responses. This study revealed that young individuals with PTSD exhibit abnormal, peripherally mediated exercise responses that may be linked to a redox imbalance.

Does mild chronic obstructive pulmonary disease need a standard pulmonary rehabilitation program? A case report

Background: Patients with mild chronic obstructive pulmonary disease (COPD) are usually not recommended for a standard pulmonary rehabilitation (PR)program based on the GOLD guideline in mild COPD GOLD A classification. Especially, the scientific evidence on exercise capacity that can be identified for recruitment in PR programs has been less reported. Thus, a preliminary case study to identify the exercise capacity under cardiopulmonary responses by aerobic exercise testing among patients in mild COPD GOLD A classification was the aim of this study. Objective: To evaluate the cardiopulmonary responses from exercise capacity testing in individual COPD patients with mild COPD GOLD A Classification. Materials and methods: Four participants with mild COPD GOLD A performed an exercise endurance capacity test at home using Spot Marching Exercise Test (SMT), marching on the spot with high hip and arm raising. The load of SMT was indicated by a controlled stepping rate at 70, 80, 90, 100, and 110 steps/min. Every participant performed Incremental SMT (ISMT) with every 3 min incremental load, and the Constant SMT (CSMT) at the peak load. Both exercise tests were terminated at symptom limit. Resting time between ISMT and CSMT was at least 30 minutes. Cardiopulmonary exercise responses, Borg perceived breathlessness (RPB) and exertion (RPE) were monitored every minute during the exercise test. The duration of exercises was recorded. Results: Peak exercise capacity using ISMT was low with the end exercise load at 70, 80, 80, and 90 steps/min which is equivalent to moderate to high intensity at 81%, 62%, 65% and 93% of age-predicted maximum heart rate (HRmax). The exercise test was stopped by breathlessness at RPB 7, 8, 6, and 5. Respiratory rates (RR) were 36, 26, 38, and 38 breaths/min. With CSMT, the results showed very short exercise duration 1.78, 4.60, 2.15, and 2.47 mins with RPB 7, 8, 5, and 5 and RR of 33, 27, 34, and 41 breaths/min respectively. Conclusion: This preliminary report reveals that all four mild COPD GOLD A show low exercise capacity and very poor exercise endurance that should identify the appropriated standard PR program in the future.

THE ACUTE EXERCISE-INDUCED INFLAMMATORY RESPONSES IN GASTROINTESTINAL DISORDERS

INTRODUCTION &amp; AIMS Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), are characterised by intestinal inflammation that presents severe symptoms and continued complications throughout the lifespan. These gastrointestinal (GI) disorders have a growing prevalence worldwide with no known cure. Management strategies often require a ‘trial and error’ process before an effective pharmacal/s is established; the successful interim varies considerably with prevalent adverse side-effects and gradual decline in the effectiveness of medication. Accordingly, alternative mechanisms to complement management options, reduce side-effects, and improve well-being warrant investigation. Physical activity is known to be beneficial for a variety of inflammatory conditions; the advantageous effects are associated with the exercise-induced inflammatory response directly from active muscle tissue. Despite this knowledge, minimal studies have attempted to quantify the inflammatory effect of exercise. This study investigates the inflammatory response of acute exercise. METHODS Participants were allocated into one of two groups: GI disorders (IBD &amp; IBS; n = 11) or apparently healthy control (AHC; n = 11). All participants completed three sessions: 1) initial familiarisation: questionnaires, anthropometry measures, DEXA scan, and a graded exercise test; 2) protocol 1: moderate-intensity continuous exercise; and 3) protocol 2: alternating high- and low-intensity exercise. Participants were randomly allocated to the acute exercise protocols. Each protocol had a fasted pre-exercise venous blood sample, 35-minutes cycle, fasted blood sample immediately post-, 2hrs post-, and 24hr post-exercise. RESULTS Significant differences were observed between groups in body mass index, waist and hip circumstances, percentage of fat mass, and VO2peak (p &amp;lt; .05). Analyses of venous blood samples will be presented. CONCLUSION With no known cure, lifestyle management is important for those with GI disorders. Exercise hosts several benefits; however, given the inflammatory nature of the condition, the acute responses of exercise are important for clinicians working with IBD/IBS patients.

Fat loss and muscle gain: The possible role of cortical glutamate in determining the efficacy of physical exercise

BackgroundPhysical exercise is widely acknowledged for its health benefits, but its effectiveness in treating obesity remains contentious due to variability in response. Owing to the roles of glutamate in appetite regulation, food addiction, and impulsivity, this observational cohort-study evaluated medial prefrontal cortex (mPFC) glutamate as a predictor of variability in exercise response, specifically in terms of fat loss and muscle gain. MethodsHealthy non-exercising adult men (n = 21) underwent an 8-week supervised exercise program. Baseline glutamate levels in the mPFC were measured through magnetic resonance spectroscopy. For exercise-dependent changes in body composition (fat and muscle mass), basal metabolic rate (BMR), and blood metabolic biomarkers related to lipid and glucose metabolism, measurements were obtained through bioelectrical impedance and blood sample analyses, respectively. ResultsThe exercise program resulted in significant improvements in body composition, including reductions in percentage body fat mass, body fat mass, and waist-to-hip ratio and an increase in mean muscle mass. Furthermore, BMR and metabolic indicators linked to glucose and lipids exhibited significant changes. Notably, lower baseline glutamate levels were associated with greater loss in percentage body fat mass (r = 0.482, p = 0.027), body fat mass (r = 0.441, p = 0.045), and increase in muscle mass (r = −0.409, p = 0.066, marginal) following the exercise program. ConclusionThese preliminary findings contribute to our understanding of the neurobiology of obesity and emphasize the significance of glutamate in regulating body composition. The results also highlight cortical glutamate as a potential predictor of exercise-induced fat loss and muscle gain.